If you want the coffee to be strong, why not extract it for a while?

In daily life, Qianjie often meets some friends who like coffee with a strong taste, and they usually ask for more shot, but one guest said, "could you help me to extract my coffee a little longer?"

According to this friend's understanding, the longer the extraction time, the more coffee liquid will be obtained, and the higher the concentration of coffee in the cup will be. is that really the case? Don't worry, let's have a little experiment first.

On the basis of the parameters of the same day, Qianjie intercepted the corresponding concentrated liquid weight at three different time points by controlling the grinding scale and the amount of powder, and then tested the coffee concentration of each group and tasted its taste. (experimental premise: espresso is calculated by weight, not by volume. )

Coffee beans: sunflower warm Italian matching coffee bean grinding scale: Galileo Q18 scale 2.0 powder quantity: 20 grams extraction time: 30 seconds, 35 seconds, 40 seconds

The first group: 35 grams of coffee solution was extracted in 30 seconds, and the TDs value was 12.11%. The flavor is mainly sour berries and fermented wine, accompanied by the mellow bitterness of cocoa, and the finish is a roasted aroma of vanilla and nuts.

The second group: 46 grams of coffee solution was extracted in 35 seconds, and the test TD value was 8.83%. The flavor is mainly caramel, cocoa and a slight wine, with a sour taste and an almond-like bitter finish.

The third group: 55 grams of coffee solution was extracted in 40 seconds, and the test TD value was 7.80%. The entrance has the lowest viscosity and unpleasant flavor, mainly composed of mugi-cha and wood tone, almost no acid, and slightly choking discomfort after swallowing.

Next, let's take a closer look at the complete extraction process to see how the state of the concentrate changes, and to intercept the front, middle and back segments of the coffee with three cups.

From the first drop of concentration, it is as thick as hot chocolate, dark brown, and the most intense, with a sharp sour taste; then the color becomes lighter and tends to golden yellow, the flow rate is also gradually larger, the concentration is not as high as the first cup, and the taste is more balanced. When the electronic scale shows more than 35 grams, the liquid is completely yellow, and the oil begins to whiten and solidify. The latter stage of the concentrated entrance is a light bitter and sweet coffee flavor, with the weakest aroma.

Like the proportion of powder and water often mentioned in hand flushing, if you want coffee to taste good, you must grasp the appropriate extraction, that is, there is no insufficient extraction but extraction. The difference is that because the output of Italian coffee machine is difficult to measure directly, people in the industry are more used to using the ratio of powder to liquid to judge and measure the reference amount of Italian concentrated extraction concentration.

The ratio of powder to liquid is affected by two factors, one is the amount of coffee powder, the other is the weight of coffee liquid. Generally, the recommended powder-to-liquid ratio for extraction is between 1RV 1.5 to 1Rd 2.5. It is more common to use a ratio of 1:2. For example, the original product parameter of Qianjie is to extract 40g coffee liquid with 20g coffee powder, while the powder-to-liquid ratio of the second and third groups in the experiment is 1VR 2.3 and 1RO 2.75 respectively, much higher than the initial value.

In theory, a delicious cup of coffee should be a moderate soluble aroma brought out by hot water. The golden cup criterion holds that the extraction rate of coffee is in the range of 18-22%, and the extraction of coffee is delicious. When the oil turns yellow until it turns white, it tells us that all the delicious substances in the coffee have been released and it's almost time to stop the extraction. If the hot water continues to scour the powder layer at this time, all that is left is the unpleasant bitter macromolecules that enter the cup with the liquid.

Combined with the previous experimental data, we can draw a conclusion that when the degree of grinding and the amount of powder are constant, and the liquid weight begins to exceed the maximum threshold of the original ratio of powder to liquid (tasty), with the increase of extraction time, the more concentrated liquid is concentrated, which means that the more hot water passes through the coffee powder, the more soluble substances are extracted, so the extraction rate is higher. At the same time, the more water also means that the coffee is diluted more, so the concentration is lower, and the positive coffee flavor is less.

For this reason, if you want an espresso base that tastes delicious and tastes stronger, it is obviously unreliable for baristas to extract a little more liquid coffee. If you don't want to add more concentrate, you might as well ask the other party if you can replace the Espresso with a very concentrated concentrate, yes, just like the Ristretto mentioned in the front street yesterday.

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Front Street Cafe

No. 10 Baoqian street, Yandun road, Dongshankou, Yuexiu district, Guangzhou, Guangdong province